Press brake guard

ABSTRACT

A safety guard for a pressing brake into which a work piece is inserted manually by an operator standing in front of the machine comprises a horizontal bar disposed between the machine and the operator at somewhat above waist height so as to serve as a stop for the operator&#39;s forearms as he manually inserts the work piece. The bar is adjustable vertically and horizontally toward and away from the machine to compensate for differences in the &#34;reach&#34; of the operator so that engagement of the operator&#39;s forearms with the bar will prevent insertion of the operator&#39;s hands into the pressing area.

This invention relates to safety guards for preventing entry of anoperator's hands into the working area of machines such as pressingbrakes.

BACKGROUND AND SUMMARY OF THE INVENTION

Pressing machines of the kind which operate on a work piece insertedinto the machine by hand are inherently a source of injury to theoperator due to the possibility of the operator accidentally insertinghis hands or fingers into the working area of the machine. The workingarea in a typical pressing machine is the area between a fixedhorizontal bed and a vertically movable ram which descends during apressing operation to shape a work piece such as metal sheet against thebed. In many operations the work piece is manually grasped along oneedge by the operator and is placed on the bed while the ram is up. Theoperator may release the work piece at this point or he may continue tohold the edge of the work piece if the edge lies outside the path oftravel of the ram. In either case there is the possibility that theoperator's hands or fingers can accidentally be caught between the ramand the work piece or the bed as the shaping operation is carried out.

It is known to provide guards for pressing machines of this type whichblock access to the work area and thereby prevent entry of both workpiece and the operator's hands into the work area. These guards, oftenconstructed in the form of a cage-like structure must be removed in partor in whole before a pressing operation can be carried out, and theytherefore do not prevent entry of the operator's hands or fingers intothe work area.

The present invention provides a guard for this type of machine which isconstructed and arranged to serve as a stop to be engaged by theoperator's arms as he extends his arms toward the machine's work area.While not obstructing the passage of the work piece into the work area.The principal element of the guard is a horizontal bar extending alongthe length of the work area and disposed between the latter and theoperator at an elevation above the bed of the machine and somewhat abovewaist height. In this position there is sufficient space below the barto permit the work piece in the hands of the operator to pass under thebar and into the work area. As the work piece approaches the work areathe operator's forearms approach the bar and contact the same before hishands enter the work area. By previously adjusting the elevation of thebar and its proximity to the work area it is possible to compensate fordifferences in the "reach" of the operator resulting from variations inthe height and arm length of different operators.

In the preferred construction the guard includes the horizontal guardbar, an arm fixed at each end of the bar extending toward the machine,two fixed upright support posts spaced apart a distance equal to thedistance between the arms, and connecting means between the inner endsof the arms and the upper ends of the posts for effecting adjustment ofbar in a vertical plane parallel to the plane of the posts and in ahorizontal plane toward and away from the machine. In this arrangmentthe support posts can be located quite close to the machine so as not toconstitute an obstruction. In addition the arms at the ends of the barprevent accidental insertion of a person's hands into the work area fromthe sides of the machine.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT

In the drawings:

FIG. 1 is a side elevation of a guard assembly embodying the principlesof the invention; and

FIG. 2 is a plan view of the guard assembly of FIG. 1.

In the drawings the guard assembly 10 is shown in association with aschematically illustrated pressing machine 12 of the kind having a fixedhorizontal bed 14 and a vertically movable ram 16. During operation ofsuch a machine a work piece 18 is manually inserted by an operator 20into a work area 22 between the bed 14 and the ram 16 and the latter iscaused to move downwardly as by mechanical or similar pressure to shapethe work piece 18. Movement of the ram can be activated by the operatorin any conventional way as by means of a foot pedal 24.

The guard assembly includes a horizontal guard bar 26 which as shown inFIG. 1 is coextensive with the length of the ram 16 and is positioned infront of the press 12 so as to limit movement of the operator's arms 28toward the work area 22. In the illustrated embodiment of the bar 26 isa length of pipe, and the other parts of the assembly are constructed ofpieces of pipe and standard pipe fittings such as 90° elbows and streetelbows, although these materials of construction are not in any waycritical to the invention.

At each end of the guard bar 26 there is a rigid horizontal arm 30extending toward the press 12. The inner end of each arm 30, that is theend nearest the press 12, slidably telescopes over a horizontal leg 32of an angle member 33 so that the bar 26 can be adjusted in a horizontalplane toward and away from the press 12. Each of the arms 30 can bereleasably locked to its respective leg 32 in any of several horizontalpositions. In the illustrated embodiment a hex head bolt 34 is threadedthrough the arm 30 into engagement with the leg 32. The legs 32 may beprovided with longitudinally spaced-apart holes 36 or depressions toreceive the inner ends of the bolts 34.

Each angle member 33 also includes a vertical leg 38 which is slidablytelescoped into the upper end of a fixed upright post 40 so that themembers 33 and the bar 26 can be adjusted in a vertical plane. The posts40 are secured at their lower ends thru the use of attaching sockets 48to the base of the press or to some other fixed structure. Releasablelatching means are provided in the form of hex head bolts 44 which arethreaded through the walls of the posts into engagement with holes 46 inthe legs 38.

In use the guard bar 26 is adjusted horizontally and vertically to aposition such that it serves as a stop which limits movement of theoperator's arms 28 toward the work area 22 when inserting the work piece18 into the latter. That is, as the operator 20 moves his arms 28 towardthe press 12, with the work piece held in hands, his forearms willapproach and engage the bar 26 as illustrated in FIG. 1. In order forthis to occur the bar 26 must be located above the bed 12 of the pressand spaced horizontally therefrom a sufficient distance for theoperator's hands and the work piece 18 to pass underneath the bar 26.The vertical and horizontal position of the bar 26 must also be suchthat engagement of the operator's forearms 28 with the bar 26 will occurwhen the operator's hands are still in front of the work. It is alsoimportant that the bar 26 be high enough and close enough to the press12 that it will be essentially impossible for an operator to place hisarms over the bar 26 when inserting the work piece 18 into the work area22.

What is claimed is:
 1. In combination with a pressing machine having avertically movable ram which cooperates with a bed or the like to shapea work piece manually inserted between the ram and the bed by anoperator, a safety guard for preventing entry of the operator's handsbetween the ram and the bed comprising a horizontal bar which isgenerally coextensive with the horizontal dimension of the ram and bedand a support assembly for said bar for supporting said bar in aposition spaced from the machine and between the machine and an operatorsuch that the bar is engaged by the operator's arms as the operatorextends his hands and arms toward the machine, said support assemblyincluding means for adjusting the vertical position of the bar relativeto the machine and means for adjusting the horizontal position of thebar in a direction transverse to the length of the bar.
 2. Apparatus asin claim 1 wherein each end of said bar carries a fixed horizontal armprojecting generally toward the machine and wherein said supportassembly includes two spaced-apart fixed upright members, a first anglemember having two legs one of which is disposed in parallel slidableengagement with one of the upright members and the other of which is inparallel slidable engagement with one of said arms, a second anglemember having two legs one of which is disposed in parallel slidableengagement with the other upright members and the other of which is inparallel slidable engagement with the other of said arms, meansreleasably locking each upright member to its respective leg and meansreleasably locking each arm to its respective leg.
 3. A guard for apressing machine comprising a horizontal bar having a horizontal arm ateach end projecting at generally a right angle to the bar, two fixedupright members spaced-apart a distance about equal to the length of thebar, first and second angle members each having a first leg disposedgenerally coaxial with and connected to one of the upright members and asecond leg disposed generally coaxial with the other upright member andeach of said angle members having a second leg disposed generallycoaxial with and connected to one of the arms, means releasably lockingeach upright member to its respective leg at a variety of coaxialpositions, and means releasably locking each arm to its respective legat a variety of coaxial positions, whereby the bar may be adjusted invertical and horizontal planes.
 4. A guard as in claim 3 wherein saidfirst legs and their respective upright members are telescopicallyconnected and wherein said second legs and their respective arms aretelescopically connected.